Scorch, i.e., premature crosslinking, in water curable resin systems is a widely recognized problem. It can result in numerous ways. The most difficult to control can be referred to as process scorch, which takes place in the presence of a silanol condensation catalyst. Process scorch is manifested just after the addition of the silanol condensation catalyst to the resin and, again, during the continuous processing of the water curable resin in, for example, an extruder. The former occurs with a rapid build up in viscosity and, in many cases, can be dramatic. The latter, generally, involves a more subtle build up of viscosity over time. In both cases, the extrusion is rendered difficult and ultimately results in an unacceptable extrudate and a shutdown of the operation.
The art is constantly searching for processes and compositions which lead to a diminution or elimination of process scorch.